Introduction

This analysis explores relationships between indicators across countries such as percentage of agricultural land, CO2 emissions per capita, and size of surface area using World Bank data. It is divided into two main parts, with this script focusing on the second question. For further observation of the first question, refer to the file ‘Analysis/agriculture.Rmd’.

1. Is there a relationship between the percentage of agricultural land and CO2 emissions per capita across countries?

2. Does the size of the surface area of the country play a role?

2. Influence of surface area on previous relationship

One further aspect that might change the non-relationship recorded in the ‘agriculture.Rmd’ file is the introduction of another variable to take into account, namely the countries’ surface areas.

Starting with the initial comparison between the variables within the ranges of the data observed, we get the following first overview.

##     Min.  1st Qu.   Median     Mean  3rd Qu.     Max. 
##      180   243610   796100  2461119  1285220 17098250


As we can see, there are several countries with no changes in surface area throughout the interested time span at all. Therefore, before heading forward, we first want to zoom in a little closer on those with changes.

## Anzahl der Länder ohne Veränderungen:  10



For the vast majority of the countries, the changes can be classified as under 1000 square kilometers over the whole time span. Similar insights can be derived when looking at the relative changes.


For each country, even those with changes throughout the time span, there are at most marginal changes of two percent in surface area. To finally confirm those claims, we take a look at the scatter decomposition. 

## Streuung zwischen den Ländern:  1.783129e+13


In conclusion, we recognize that the changes in surface area are negligible over time. Therefore, we drop our focus on the development over time considering this variable when moving on. More interesting might be shifting the perspective towards whether the absolute amount of surface area has any influence on the relationship between agricultural land and CO2 emissions for the observed countries.

For this exploration, we want to distinguish our countries into the following groups:
We see there is no direct influence obvious through the grouping of the data. Let’s dig deeper by looking at the time-specific distribution.
The biggest anomalies regarding the CO2 emissions with the percentage of agricultural land in mind seem to be the moderate and very large surface area countries. Here on one hand, we can detect comparably high percentages in agricultural land for the moderate area countries, but those do not transfer themselves to any obvious differences in the CO2 emissions compared to the other groups. On the other hand, the very large countries stand out by having the supposedly expectable highest CO2 emissions among all groups. Marginal differences appear between the development over time, as the very large area countries are constant over the two decade timespan, while the other groups have slightly increasing trends.
If we finally pivot back to our normalized comparison we did earlier, we can do the same now with our grouped data according to the surface area categories.


We cannot identify any obvious connection between the CO2 emissions per capita and the percentage of agricultural land even with the interested countries categorized by surface area.